Pi Misconception

Happy Pi day folks !
Heres a general misconception im having. It might turn out to be a pretty easy question so please do help me.

If i pull out my compass to a radius of 7 cm and draw a circle on a paper. Then i'll take a piece of thread and cut it such that it matches exactly with the circle on paper and take the length of that particular thread and divide by 14cm, should i get the value of pi ?

If its so, why isnt pi an irrational number. After all im dividing the circumfrence i've got by 14 cm.
So it should a rational number.

For example, if the circumfrence is 50.123456 cm ( i've not measured yet just an example)
And i divide it by 14cm

I shall get 50123456/14000000 as value of pi, which is supposedly rational ?

For example, if the circumfrence is 50.123456 cm ( i've not measured yet just an example)

How would you manage to measure it to such precision? There are many reasons why an irrational number like pi will be approximated to a rational number with real world measurements. Hypothetically, it should be pi, but realistically, it's impossible to do.

Happy Pi day folks !
Heres a general misconception im having. It might turn out to be a pretty easy question so please do help me.

If i pull out my compass to a radius of 7 cm and draw a circle on a paper. Then i'll take a piece of thread and cut it such that it matches exactly with the circle on paper and take the length of that particular thread and divide by 14cm, should i get the value of pi ?

If its so, why isnt pi an irrational number.

You mean why is pi an irrational number. Or why isn't pi a rational number.

After all im dividing the circumfrence i've got by 14 cm.
So it should a rational number.

For example, if the circumfrence is 50.123456 cm ( i've not measured yet just an example)
And i divide it by 14cm

I shall get 50123456/14000000 as value of pi, which is supposedly rational ?

Is it an contradiction ?

No, a "measurement" is never exact. When you talk about "lengths" in geometry you are not talking about measurements.